Novel self-reversible reverse microlatex, process for preparing it and cosmetic and industrial uses thereof

ABSTRACT

Composition comprising an oil phase, an aqueous phase, at least one surfactant of water-in-oil (W/O) type, at least one surfactant of oil-in-water (O/W) type and a branched or crosslinked polyelectrolyte, characterized in that:  
     (a) the said composition is a self-reversible reverse microlatex comprising from 15% to 40% by weight and preferably from 20% to 30% by weight of the said polyelectrolyte,  
     (b) the said polyelectrolyte is either a homopolymer based on a monomer containing a strong acid function, which is partially or totally salified or a weak acid function which is partially or totally salified, or a copolymer based on at least one monomer containing a strong acid function, which is copolymerized either with at least one monomer containing a weak acid function or with at least one neutral monomer, or a copolymer based on at least one monomer containing a weak acid function, which is copolymerized with at least one neutral monomer, or a copolymer based on at least one monomer containing a strong acid function, which is copolymerized with a monomer containing at least one weak acid function and with at least one neutral monomer, and  
     (c) the mixture of the said surfactant of water-in-oil (W/O) type and of the said surfactant of oil-in-water (O/W) type has a total HLB number of greater than or equal to 8.5 and less than or equal to 11 and preferably greater than or equal to 9.5 and less than or equal to 10.  
     Uses in cosmetics and as an industrial emulsifier and/or thickener.

[0001] The present patent application relates to thickening water-in-oil self-reversible reverse microlatices, to a process for preparing them and to their use as thickeners and/or emulsifiers for skincare and haircare products or for manufacturing cosmetic, dermopharmaceutical or pharmaceutical preparations, or textile treatment formulations.

[0002] Among the various existing thickeners used for thickening aqueous phases, there are polymers in powder form such as those described in the patent applications published under Nos. EP 0 341 660, EP 0 321 650 and EP 0 341 662 or the polymers described in FR 2 810 545.

[0003] Among the various existing thickeners for thickening aqueous phases, there are reverse emulsions of polymers such as those described in the patent applications published under Nos. EP 0 161 038, EP 0 503 853 or FR 2 790 759.

[0004] However, most of these thickeners have the drawback of still being very sensitive to the presence of salts.

[0005] In the course of research into the development of new polymers that are more resistant to the presence of salts, the Applicant became more particularly interested in reverse microemulsions of polymers and has found, unexpectedly, that some of them have improved stability to salts.

[0006] Accordingly, a subject of the invention is a composition comprising an oil phase, an aqueous phase, at least one surfactant of water-in-oil (W/O) type, at least one surfactant of oil-in-water (O/W) type and a branched or crosslinked polyelectrolyte, characterized in that

[0007] (a) the said composition is a self-reversible reverse microlatex comprising from 15% to 40% by weight and preferably from 20% to 30% by weight of the said polyelectrolyte,

[0008] (b) the said polyelectrolyte is either a homopolymer based on a monomer containing a strong acid function, which is partially or totally salified, or a copolymer based on at least one monomer containing a strong acid function, which is copolymerized either with at least one monomer containing a weak acid function or with at least one neutral monomer, or a copolymer based on at least one monomer containing a weak acid function, which is copolymerized with at least one neutral monomer, or a copolymer based on at least one monomer containing a strong acid function, which is copolymerized with a monomer containing at least one weak acid function and with at least one neutral monomer, and

[0009] (c) the mixture of the said surfactant of water-in-oil (W/O) type and of the said surfactant of oil-in-water (O/W) type has a total HLB number of greater than or equal to 8.5 and less than or equal to 11 and preferably greater than or equal to 9.5 and less than or equal to 10.

[0010] The expression “surfactant of the water-in-oil type” denotes surfactants having an HLB value that is low enough to give water-in-oil emulsions, such as surfactant polymers of the polyethylene glycol poly(hydroxystearic acid) block copolymer type, sold under the name Hypermer™, such as sorbitan esters, for instance the sorbitan monooleate sold by the Applicant under the name Montane 80™, the sorbitan isostearate sold by the Applicant under the name Montane 70™, the sorbitan oleate ethoxylated with 5 mol of ethylene oxide (5 EO) sold by the Applicant under the name Montane™ 81, the diethoxylated (2 EO) oleocetyl alcohol sold by the Applicant under the name Simulsol™ OC 72 or the sorbitan sesquioleate sold by the Applicant under the name Montane™ 83.

[0011] The expression “surfactant of the oil-in-water type” denotes surfactants with an HLB value that is high enough to give oil-in-water emulsions such as ethoxylated sorbitan esters, for instance the sorbitan oleate ethoxylated with 20 mol of ethylene oxide (20 EO) sold by the Applicant under the name Montanox™ 80, the castor oil ethoxylated with 40 mol of ethylene oxide (40 EO) sold by the Applicant under the name Simulsol™ OL 50, the sorbitan laurate ethoxylated with 20 mol of ethylene oxide (20 EO), sold by the Applicant under the name Montanox™ 20, the sorbitan trioleate ethoxylated with 25 mol of ethylene oxide (25 EO) sold by the Applicant under the name Montanox™ 85, the lauryl alcohol ethoxylated with 7 mol of ethylene oxide (7 EO), sold by the Applicant under the name Simulsol™ P 7, the decaethoxylated (10 EO) oleocetyl alcohol sold by the Applicant under the name Simulsol™ OC 710 or the polyethoxylated sorbitan hexaoleoates sold under the names G-1086™ and G-1096™.

[0012] For the purposes of the present invention, the HLB number is calculated by means of the formula HLB=20 (1-I_(s)/I_(a)), in which I_(s) represents the saponification number of the surfactant or of the mixture of surfactants and I_(a) represents the acid number of the starting fatty acid or of the mixture of starting fatty acids, as described by N. Schönfeld in the brochure entitled “Surface active ethylene oxide adducts” (page 228).

[0013] The term “branched polymer” denotes a non-linear polymer containing pendent chains so as to obtain, when this polymer is dissolved in water, a high degree of interlinking leading to very high viscosities at low rate gradient.

[0014] The term “crosslinked polymer” denotes a non-linear polymer in the form of a three-dimensional network, which is insoluble in water but swellable in water and thus leading to the production of a chemical gel.

[0015] The acid function of the monomer comprising it is especially the sulphonic acid function or the phosphonic acid function, which is partially or totally salified. The said monomer may be, for example, partially or totally salified styrene sulphonic acid or, preferably, partially or totally salified 2-methyl-2[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid, especially in the form either of an alkali metal salt, for instance a sodium or potassium salt, or of an ammonium salt, or amino alcohol salt, for instance the monoethanolamine salt or an amino acid salt, for instance the lysine salt.

[0016] The weak acid function of the monomer comprising it is especially the carboxylic acid function, and the said monomer is preferably chosen from acrylic acid, methacrylic acid, itaconic acid, maleic acid or 3-methyl-3-[(1-oxo-2-propenyl)amino]butanoic acid, the said acids being partially or totally salified especially in the form either of an alkaline metal salt, for instance the sodium salt or the potassium salt, or of an ammonium salt, or an amino alcohol salt, for instance the monoethanolamine salt, or an amino acid salt, for instance the lysine salt.

[0017] The neutral monomer is especially chosen from acrylamide, 2-hydroxyethyl acrylate, 2,3-dihydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-3-dihydroxypropyl methacrylate or an ethoxylated derivative with a molecular weight of between 400 and 1 000, of each of these esters.

[0018] According to a first particular aspect of the present invention, the polyelectrolyte included in the self-reversible reverse microlatex as defined above is a crosslinked 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid homopolymer partially or totally salified in the form of the sodium salt or the ammonium salt.

[0019] According to a second particular aspect of the present invention, the polyelectrolyte included in the self-reversible reverse microlatex as defined above, is a crosslinked copolymer of acrylic acid partially or totally salified in the form of the sodium salt or the ammonium salt (a) and of acrylamide (b), in an (a)/(b) molar ratio of between 10/90 and 90/10.

[0020] According to a third particular aspect of the present invention, the polyelectrolyte included in the self-reversible reverse microlatex as defined above is a crosslinked copolymer of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid partially or totally salified in the form of the sodium salt, the ammonium salt, the monoethanolamine salt or the lysine salt (a) and of 2-hydroxyethyl acrylate (b), in an (a)/(b) molar ratio of between 30/70 and 90/10 and most particularly between 50/50 and 90/10.

[0021] According to a fourth particular aspect of the present invention, the polyelectrolyte included in the self-reversible reverse microlatex as defined above is a crosslinked copolymer of the sodium salt, the ammonium salt, the monoethanolamine salt or the lysine salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid (a) and of acrylic acid partially or totally salified in the form of the sodium salt, the ammonium salt, the monoethanolamine salt or the lysine salt (c), in an (a)/(c) molar ratio of between 30/70 and 90/10 and most particularly between 30/70 and 45/55.

[0022] According to a fifth particular aspect of the present invention, the polyelectrolyte included in the reverse microlatex as defined above is a crosslinked copolymer of the sodium salt or the ammonium salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid (a) and of acrylamide (d), in an (a)/(d) molar ratio of between 50/50 and 30/70.

[0023] According to a sixth particular aspect of the present invention, the polyelectrolyte included in the self-reversible reverse microlatex as defined above is a crosslinked copolymer of the sodium salt, the ammonium salt, the monoethanolamine salt or the lysine salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid (a), of acrylic acid partially or totally salified in the form of the sodium salt, the ammonium salt, the monoethanolamine salt or the lysine salt (c) and either of acrylamide (d), or of 2-hydroxyethyl acrylate (e), in (a)/(c)+(d) or (a)/(c)+(e) molar proportions of between 10/90, 90/10 and (c)/(d) or (c)/(e) molar proportions of between 10/90 and 90/10.

[0024] A subject of the present invention is, more particularly, a composition as defined above, characterized in that the polyelectrolyte is crosslinked and/or branched with a diethylenic or polyethylenic compound in a molar proportion, expressed relative to the monomers used, of from 0.005% to 1%, more particularly from 0.01% to 0.5% and most particularly from 0.1% to 0.25%. The crosslinking agent and/or the branching agent is chosen from diallyoxyacetic acid or a salt thereof, for instance sodium diallyloxyacetate, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diallylurea, trimethylolpropane triacrylate, methylenebis(acrylamide), triallylamine, and diallyl tartramide, or a mixture of these compounds.

[0025] The self-reversible reverse microlatex according to the invention generally contains between 8% and 20% by weight of surfactants.

[0026] The composition as defined above is characterized in that the oil phase represents from 25% to 50% and more particularly from 30% to 40% of its total weight.

[0027] This oil phase consists either of a commercial mineral oil containing saturated hydrocarbons, paraffins, isoparaffins or cycloparaffins, having at room temperature a density of between 0.7 and 0.9, and a boiling point of greater than 180° C., for instance Exxsol™ D100 S or Marcol™52 sold by Exxon Chemical, isohexadecane or isododecane, or of a plant oil, for instance squalane, or of a synthetic oil, for instance hydrogenated polyisobutene, or of a mixture of several of these oils.

[0028] Isohexadecane, which is identified in Chemical Abstracts by No. RN=93685-80-4, is a mixture of C₁₂, C₁₆ and C₂₀ isoparaffins containing at least 97% of C₁₆ isoparaffins, among which the main constituent is 2,2,4,4,6,8,8-heptamethylnonane (RN=4390-04-9). It is sold in France by the company Bayer. Marcol™52 is a commercial oil corresponding to the definition of liquid petroleum jellies in the French Codex. It is a white mineral oil in accordance with the regulations FDA 21 CFR 172.878 and CFR 178.3620 (a) and is recorded in the US Pharmacopoeia, US XXIII (1995) and in the European Pharmacopoeia (1993).

[0029] The self-reversible reverse microlatices according to the invention contain between 15% and 50% by weight of water.

[0030] The self-reversible reverse microlatices according to the invention may also contain various additives such as complexing agents, transfer agents or chain-limiting agents.

[0031] According to another aspect of the present invention, the invention relates to a process for preparing a reverse microemulsion of the polymer as defined above, characterized in that:

[0032] a) an oil phase and surfactants are added, with stirring to an aqueous solution containing the monomers and the optional additives, so as to form a reverse microemulsion, and then

[0033] b) the polymerization reaction is initiated and the said reaction is then left to proceed to form the reverse microlatex.

[0034] According to one preferred embodiment of the process as defined above, the polymerization reaction is initiated by a redox couple, such as the cumin hydroperoxide/sodium metabisulphite couple, at a temperature of less than or equal to 20° C., and then formed either virtually adiabatically up to a temperature of greater than or equal to 40° C., more particularly greater than or equal to 50° C., or by controlling the change in temperature.

[0035] A subject of the invention is also a cosmetic, dermopharmaceutical or pharmaceutical composition, characterized in that it comprises at least one reverse microlatex as defined above as thickening and/or emulsifying compound.

[0036] The cosmetic, dermocosmetic, dermopharmaceutical or pharmaceutical composition defined above generally comprises from 0.1% to 10% and more particularly between 0.5% and 5% by weight of the said reverse microlatex. It is especially in the form of a milk, a lotion, a gel, a cream, a soap, a bubble-bath, a balm, a shampoo or a conditioner.

[0037] In general, the said reverse microlatex may advantageously replace the products sold under the name Sepigel™ 305 or Sepigel™ 501 by the Applicant, in cosmetic, dermopharmaceutical or pharmaceutical compositions, since it also shows good compatibility with the other excipients used for preparing formulations such as milks, lotions, creams, soaps, bubble-baths, balms, shampoos or conditioners. It may also be used in combination with the said Sepigel products. It is especially compatible with the concentrates described and claimed in the international publications WO 92/06778, WO 95/04592 and WO 95/13863 or FR 2 734 496 or with the surfactants described in WO 93/08204. It is particularly compatible with Montanov™ 68, Montanov™ 82, Montanov™ 202, Montanov™ WO18, Montanov™ S or Sepiperl™ N. It may also be used in emulsions of the type described and claimed in EP 0 629 396 and in cosmetically or physiologically acceptable aqueous dispersions with an organopolysiloxane compound chosen, for example, from those described in WO 93/05762 or in WO 93/21316. It may also be used to form cosmetically or physiologically acceptable aqueous gels at acidic pH, such as those described in WO 93/07856; it may also be used in combination with nonionic celluloses, for example to form styling gels, such as those described in EP 0 684 024 or in combination with fatty acid esters of sugars, to form compositions for treating the hair or the skin such as those described in EP 0 603 019, or in shampoos or conditioners as described and claimed in WO 92/21316 or, finally, in combination with an anionic homopolymer, such as the Carbopol™ products to form hair treatment products, for instance those described in DE 195 23 596. It is also compatible with numerous active principles, for instance self-tanning agents such as dihydroxyacetone (DHA) or antiacne agents; it may thus be introduced into self-tanning compositions such as those claimed in EP 0 715 845, EP 0 604 249 or EP 0 576 188 or in WO 93/07902. It is also compatible with N-acyl derivatives of amino acids, which allows its use in calmant compositions especially for sensitive skin, such as those described or claimed in WO 92/21318, WO 94/27561 or WO 98/09611. It is also compatible with glycolic acids, with lactic acid, with salicylic acid, retinoids, phenoxyethanol, sugars, glyceraldehyde, xanthans, fruit acids, and the various polyols used in the manufacture of cosmetic formulations.

[0038] A subject of the invention is thus also the use of a reverse microlatex as defined above as an emulsifier and/or thickener, in the preparation of a cosmetic, dermocosmetic, dermopharmaceutical or pharmaceutical composition.

[0039] According to a final aspect of the present invention, a subject of this invention is the use of the composition as defined above as a thickener and/or emulsifier in preparations intended for industries of all kinds, whether it is, for example, the textile industry, the paper industry or the paint manufacturing industry.

[0040] According to a particular aspect of this final aspect of the present invention, its subject is the use of a self-reversible reverse microlatex as a thickener for printing pastes or for paint manufacture, and more particularly as a thickener for printing pastes based on pigments or dyes. Such pastes are especially used in the textile industry. The examples that follow are aimed at illustrating the present invention without, however, limiting it.

EXAMPLE 1 Preparation and Properties of the Reverse Microlatex (A) According to the Invention

[0041] Preparation

[0042] The following are loaded into a beaker, with stirring:

[0043] 0.26 g of methylenebis(acrylamide),

[0044] 0.45 g of a commercial solution containing 40% by weight of sodium diethylenetriaminepentaacetate,

[0045] 121.9 g of a commercial 50% acrylamide solution, and

[0046] 358.1 g of a commercial solution containing 55% by weight of the sodium salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid (55% Na ATBS).

[0047] The following are successively added to this aqueous phase, with simple stirring:

[0048] 393 g of isohexadecane,

[0049] 25.2 g of Montane™ 80 VG,

[0050] 116.2 g of Montanox™ 80,

[0051] 0.41 g of AIBN (azobis(isobutyronitrile)), and a clear reverse microemulsion is obtained.

[0052] The microemulsion obtained is transferred into a polymerization reactor and nitrogen is bubbled through for 1 hour. 2.4 g of a solution containing 1% by weight of cumin hydroperoxide in isohexadecane are then added, followed by addition of an aqueous sodium metabisulphite solution (0.2 g in 100 ml of water) at a rate of 0.5 ml/minute. The introduction is performed over about 10 minutes. At the end of polymerization, a transparent, stable self-reversible reverse microlatex is obtained.

[0053] Evaluation of the Properties

[0054] Viscosity of the self-reversible reverse microlatex containing 1% polymer in water (Brookfield RVT, spindle No. 5; speed: 5 rpm): η=98 000 mPa.s;

[0055] Viscosity of the self-reversible reverse microlatex containing 1% polymer in water+0.1% NaCl (Brookfield RVT, spindle No. 5; speed: 5 rpm); η=29 400 mPa.s;

[0056] Ratio R: viscosity in the saline solution/viscosity in water=0.3.

[0057] For comparative purposes, the viscosities at 1% in water and at 1% in water+0.1% NaCl, of a self-reversible reverse latex of a crosslinked copolymer prepared with the same monomers in the same molar proportions (50/50 acrylamide/ATBS) and the same crosslinking agent (methylenebis(acrylamide)), in the same oil (ioshexadecane), were measured. The results are given in the table below. Self-reversible reverse Self-reversible microlatex reverse latex (invention) (prior art) Viscosity at 1% in water 98 000 mPa s 74 800 mPa s (RVT spindle 6, speed 5) Viscosity at 1% in water + 29 400 mPa s  4 400 mPa s 0.1% NaCl (RVT spindle 5, speed 5) Ratio R 0.3 0.06

[0058] These results show that the reverse microlatex of the invention is much more stable to salt than the reverse latex of the same copolymer in the same oil at similar concentrations.

EXAMPLE 2 Preparation and Properties of the Reverse Microlatex (B) According to the Invention

[0059] Preparation

[0060] The following are loaded into a beaker, with stirring:

[0061] 0.40 g of methylenebis(acrylamide),

[0062] 0.45 g of a commercial solution containing 40% by weight of sodium diethylenetriaminepentaacetate,

[0063] 0.55 g of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid, and

[0064] 540 g of a commercial solution containing 55% by weight of the sodium salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid (55% Na ATBS).

[0065] The following are successively added to this aqueous phase, with simple stirring:

[0066] 360 g of isohexadecane,

[0067] 17.9 g of Montane™ 80 VG,

[0068] 82.9 g of Montanox™ 85,

[0069] 0.41 g of AIBN

[0070] and a clear reverse microemulsion is obtained.

[0071] The microemulsion obtained is transferred into a polymerization reactor and nitrogen is bubbled through for 1 hour. 2.4 g of a solution containing 1% by weight of cumin hydroperoxide in isohexadecane are then added, followed by addition of an aqueous sodium metabisulphite solution (0.2 g in 100 ml of water) at a rate of 0.5 ml/minute. The introduction is performed over about 10 minutes. At the end of polymerization, a transparent, stable self-reversible reverse microlatex is obtained.

[0072] Evaluation of the Properties

[0073] Viscosity of the self-reversible reverse microlatex containing 1% polymer in water (Brookfield RVT, spindle No. 5; speed: 5 rpm): η=52 000 mPa.s;

[0074] Viscosity of the self-reversible reverse microlatex containing 1% polymer in water+0.1% NaCl (Brookfield RVT, spindle No. 5; speed: 5 rpm); η=15 000 mPa.s;

[0075] Ratio: viscosity in the saline solution/viscosity in water=0.3.

[0076] For comparative purposes, the viscosities at 1% in water and at 1% in water+0.1% NaCl, of a self-reversible reverse latex of a crosslinked homopolymer prepared with the same monomer and the same crosslinking agent (methylenebis(acrylamide), in the same oil (ioshexadecane), were measured. The results are given in the table below. Self-reversible reverse Self-reversible microlatex reverse latex (invention) (prior art) Viscosity at 1% in water 52 000 mPa s 100 000 mPa s (RVT spindle 6, speed 5) Viscosity at 1% in water + 15 000 mPa s  6 200 mPa s 0.1% NaCl (RVT spindle 5, speed 5) Ratio R 0.3 0.06

[0077] These results show that the reverse microlatex of the invention is much more stable to salt than the reverse latex of the same homopolymer in the same oil at similar concentrations.

EXAMPLE 3 Preparation and Properties of the Reverse Microlatex (C) According to the Invention

[0078] Preparation

[0079] The following are loaded into a beaker, with stirring:

[0080] 0.26 g of methylenebis(acrylamide),

[0081] 0.45 g of a commercial solution containing 40% by weight of sodium diethylenetriaminepentaacetate,

[0082] 120.2 g of a commercial 50% acrylamide solution, and

[0083] 352.8 g of a commercial solution containing 55% by weight of the sodium salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid (55% Na ATBS), and

[0084] 0.4 g of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid.

[0085] The following are successively added to this aqueous phase, with simple stirring:

[0086] 387.1 g of hydrogenated polyisobutene (PIB),

[0087] 39.7 g of Montane™ 80 VG,

[0088] 100.3 g of Montanox™ 85,

[0089]0.4 g of AIBN,

[0090] and a clear reverse microemulsion is obtained.

[0091] The microemulsion obtained is transferred into a polymerization reactor and nitrogen is bubbled through for 1 hour. 2.4 g of a solution containing 1% by weight of cumin hydroperoxide in PIB are then added, followed by addition of an aqueous sodium metabisulphite solution (0.2 g in 100 ml of water) at a rate of 0.5 ml/minute. The introduction is performed over about 10 minutes. At the end of polymerization, a transparent, stable self-reversible reverse microlatex is obtained.

[0092] Evaluation of the Properties

[0093] Viscosity of the self-reversible reverse microlatex containing 1% polymer in water (Brookfield RVT, spindle No. 6; speed: 5 rpm): η=72 000 mPa.s;

[0094] Viscosity of the self-reversible reverse microlatex containing 1% polymer in water+0.1% NaCl (Brookfield RVT, spindle No. 6; speed: 5 rpm); η=21 000 mPa.s;

[0095] Ratio: viscosity in the saline solution/viscosity in water=0.3.

[0096] C) Examples of Formulations Prepared with the Compositions According to the Invention

EXAMPLE 4 Care Cream

[0097] Cyclomethicone: 10% Reverse microlatex A:  0.8% Montanov ™68:  2% Stearyl alcohol:  1% Stearyl alcohol:  0.5% Preserving agent:  0.65% Lysine:  0.025% EDTA (disodium salt):  0.05% Xanthan gum:  0.2% Glycerol:  3% Water: q.s. 100%

EXAMPLE 5 Aftershave Balm

[0098] FORMULA A Reverse microlatex A:  1.5% Water: q.s. 100% B Micropearl ™M 100:  5.0% Sepicide ™CI:  0.50% Fragrance:  0.20% 95° ethanol: 10.0% PROCEDURE Add B to A.

EXAMPLE 6 Satin Body Emulsion

[0099] FORMULA A Simusol ™165:  5.0% Lanol ™1688:  8.50% Karite butter:  2% Liquid paraffin:  6.5% Lanol ™14M:  3% Lanol ™S:  0.6% B Water: 66.2% C Micropearl ™M 100:  5% D Reverse microlatex C:  3% E Sepicide ™CI:  0.3% Sepicide ™HB:  0.5% Monteine ™CA:  1% Fragrance:  0.20% Vitamin E acetate:  0.20% Sodium pyrrolidinonecarboxylate:  1%

[0100] Procedure

[0101] Add C to B, emulsify B in A at 70° C. and then add D at 60° C., followed by E at 30° C.

EXAMPLE 7 O/W Cream

[0102] FORMULA A Simulsol ™165:  5.0% Lanol ™1688: 20.0% Lanol ™P:  1.0% B Water: q.s. 100% C Reverse microlatex C:  2.50% D Sepicide ™CI:  0.20% Sepicide ™HB:  0.30%

[0103] Procedure

[0104] Introduce B into A at about 75° C.; add C at about 60° C., followed by D at 45° C.

EXAMPLE 8 Non-Greasy Antisun Gel

[0105] FORMULA A Reverse microlatex B:  3.00% Water: 30% B Sepicide ™CI:  0.20% Sepicide ™HB:  0.30% Fragrance:  0.10% C Dye: q.s. Water: 30% D Micropearl ™M 100:  3.00% Water: q.s. 100% E Silicone oil:  2.0% Parsol ™MCX:  5.00%

[0106] Procedure

[0107] Introduce B into A; add C, followed by D and then E.

EXAMPLE 9 Antisun Milk

[0108] FORMULA A Montanov ™S: 3.0% Sesame oil: 5.0% Parsol ™MCX: 5.0% λ-Carrageenan 0.10% B Water: q.s. 100% C Reverse microlatex A: 0.80% D Fragrance: q.s. Preserving agent: q.s.

[0109] Procedure

[0110] Emulsify B in A at 75° C., then add C at about 60° C., followed by D at about 30° C., and adjust the pH if necessary.

EXAMPLE 10 Massage Gel

[0111] FORMULA A Reverse microlatex B:  3.5% Water: 20.0% B Dye: 2 drops/100 g Water: q.s. C Alcohol: 10% Menthol:  0.10% D Silicone oil:  5.0%

[0112] Procedure

[0113] Add B to A, then add C to the mixture, followed by D.

EXAMPLE 11 Moisturizing and Matting Foundation

[0114] FORMULA A Water: 20.0% Butylene glycol:  4.0% PEG-400:  4.0% Pecosil ™PS100:  1.0% NaOH: q.s. pH = 9 Titanium dioxide:  7.0% Talc:  2.0% Yellow iron oxide:  0.8% Red iron oxide:  0.3% Black iron oxide:  0.05% B Lanol ™ 99:  8% Caprylic/capric triglyceride  8% Montanov ™ 202:  5.00% C Water: q.s. 100% Micropearl ™ M305:  2.0% Tetrasodium EDTA:  0.05% D Cyclomethicone:  4.0% Xanthan gum:  0.2% Reverse microlatex A:  0.8% E Sepicide ™ HB:  0.5% Sepicide CI:  0.3% Fragrance:  0.2%

[0115] Procedure

[0116] Prepare the mixtures B+D and A+C at 80° C., then mix together and emulsify.

EXAMPLE 12 Radiant-Effect Gel

[0117] FORMULA A Reverse microlatex C:  4% Water: 30% B Elastine HPM:  5.0% C Micropearl ™M 100:  3% Water:  5% D Sepicide ™CI:  0.2% Sepicide ™HB:  0.3% Fragrance:  0.06% 50% sodium pyrrolidinonecarboxylate:  1% Water: q.s. 100%

[0118] Procedure

[0119] Prepare A; add B, followed by C and then D.

EXAMPLE 13 Body Milk

[0120] FORMULA A Montanov ™ S: 3.5% Lanol ™ 37T: 8.0% Solagum ™ L: 0.05% Water: q.s. 100% Benzophenone: 2.0% Dimethicone 350 cPs: 0.05% Reverse microlatex B: 0.08% Preserving agent: 0.2% Fragrance: 0.4%

EXAMPLE 14 Make-Up-Removing Emulsion Containing Sweet Almond Oil

[0121] FORMULA Montanov ™68: 5% Sweet almond oil: 5% Water: q.s. 100% Reverse microlatex A: 0.3% Glycerol: 5% Preserving agent: 0.2% Fragrance: 0.3%

EXAMPLE 15 Moisturizing Cream for Greasy Skin

[0122] FORMULA Montanov ™68: 5% Cetylstearyl octanoate: 8% Octyl palmitate: 2% Water: q.s. 100% Reverse microlatex C: 0.6% Micropearl ™M100: 3.0% Mucopolysaccharides: 5% Sepicide ™HB: 0.8% Fragrance: 0.3%

EXAMPLE 16 Alcohol-Free, Soothing After-Shave Balm

[0123] FORMULA A Lipacide ™ PVB: 1.0% Lanol ™99: 2.0% Sweet almond oil: 0.5% B Reverse microlatex A: 3.5% C Water: q.s. 100% D Fragrance: 0.4% Sepicide ™HB: 0.4% Sepicide ™CI: 0.2%

EXAMPLE 17 Cream Containing AHAs for Sensitive Skin

[0124] FORMULA Mixture of laurylamino acids: 0.1% to 5% Magnesium potassium aspartate: 0.002% to 0.5% Lanol ™99: 2% Montanov ™68: 5.0% Water: q.s. 100% Reverse microlatex B: 1.50% Gluconic acid: 1.50% Triethylamine: 0.9% Sepicide ™HB: 0.3% Sepicide ™CI: 0.2% Fragrance: 0.4%

EXAMPLE 18 Aftersun Soothing Care Product

[0125] FORMULA Mixture of lauryl amino acids:  0.1% to 5% Magnesium potassium aspartate:  0.002% to 0.5% Lanol ™99: 10.0% Water: q.s. 100% Reverse microlatex A:  2.50% Sepicide ™HB:  0.3% Sepicide ™CI:  0.2% Fragrance:  0.4% Dye:  0.03%

EXAMPLE 19 Make-Up-Removing Milk

[0126] FORMULA Sepiperl ™N: 3% Primol ™ 352: 8.0% Sweet almond oil: 2% Water: q.s. 100% Reverse microlatex B: 0.8% Preserving agent: 0.2%

EXAMPLE 20 Alkaline-pH Fluid Emulsion

[0127] Marcol ™ 82:  5.0% NaOH: 10.0% Water: q.s. 100% Reverse microlatex A:  1.5%

EXAMPLE 21 Fluid Foundation

[0128] FORMULA Simusol ™165:  5.0% Lanol ™84D:  8.0% Lanol ™99:  5.0% Water: q.s. 100% Inorganic fillers and pigments: 10.0% Reverse microlatex A:  1.2% Preserving agent:  0.2% Fragrance:  0.4%

EXAMPLE 22 Antisun Milk

[0129] FORMULA Sepiperl ™ N:  3.5% Lanol ™ 37T: 10.0% Parsol ™ MCX:  5.0% Eusolex ™ 4360:  2.0% Water: q.s. 100% Reverse microlatex A:  1.8% Preserving agent:  0.2% Fragrance:  0.4%

EXAMPLE 23 Gel for Around the Eyes

[0130] FORMULA Reverse microlatex A: 2.0% Fragrance: 0.06% Sodium pyrrolidinonecarboxylate: 0.2% Dow Corning ™ 245 Fluid 2.0% Water: q.s. 100%

EXAMPLE 24 Leave-in Care Composition

[0131] FORMULA Reverse microlatex C:  1.5% Fragrance: q.s. Preserving agent: q.s. Dow Corning ™ X2 8360:  5.0% Dow Corning ™ Q2 1401: 15.0% Water: q.s. 100%

EXAMPLE 25 Slimming Gel

[0132] Reverse microlatex C:  5% Ethanol: 30% Menthol:  0.1% Caffeine:  2.5% Extract of butcher's-broom:  2% Extract of ivy:  2% Sepicide ™ HP:  1% Water: q.s. 100%

EXAMPLE 26 Ultra-Natural Tinted Cream Gel

[0133] FORMULA A Water: 10.0% Butylene glycol:  4.0% PEG-400:  4.0% Pecosil ™ PS100:  1.5% NaOH: q.s. pH = 7 Titanium dioxide:  2.0% Yellow iron oxide:  0.8% Red iron oxide:  0.3% Black iron oxide:  0.05% B Lanol ™ 99:  4.0% Caprylic/capric triglyceride:  4.0% Sepifeel ™ One:  1.0% Reverse microlatex B:  3.0% C Water: q.s. 100% Micropearl ™ M305:  2.0% Tetrasodium EDTA:  0.05% Cyclomethicone:  4.0% D Sepicide ™ HB:  0.5% Sepicide CI:  0.3% Fragrance:  0.2%

[0134] Procedure

[0135] Prepare the mixture B+C then add A, followed by D.

EXAMPLE 27 Care Product for Greasy Skin

[0136] FORMULA A Micropearl ™ M310:  1.0% Reverse microlatex A:  5.0% Octyl isononanoate:  4.0% B Water: q.s. 100% C Sepicontrol ™ A5:  4.0% Fragrance:  0.1% Sepicide ™ HB:  0.3% Sepicide ™ CI:  0.2% D Capigel ™ 98:  0.5% Water: 10%

EXAMPLE 28 Cream Containing AHAs

[0137] FORMULA A Montanov ™ 68:  5.0% Lipacide ™ PVB:  1.05% Lanol ™ 99: 10.0% B Water: q.s. 100% Gluconic acid:  1.5% TEA (triethanolamine):  0.9% C Reverse microlatex B:  1.5% D Fragrance:  0.4% Sepicide ™ HB:  0.2% Sepicide ™ CI:  0.4%

EXAMPLE 29 Non-Greasy Self-Tanning Product for the Face and the Body

[0138] FORMULA A Lanol ™ 2681: 3.0% Reverse microlatex A: 2.5% B Water: q.s. 100% Dihydroxyacetone: 3.0% C Fragrance: 0.2% Sepicide ™ HB: 0.8% NaOH (sodium hydroxide): q.s. pH = 5

EXAMPLE 30 Antisun Milk Containing Monoï de Tahiti

[0139] FORMULA A Monoï de Tahiti: 10% Lipacide ™ PVB:  0.5% Reverse microlatex B:  2.2% B Water: q.s. 100% C Fragrance:  0.1% Sepicide ™ HB:  0.3% Sepicide ™ CI:  0.1% Parsol ™ MCX:  4.0%

EXAMPLE 31 Antisun Care Product for the Face

[0140] FORMULA A Cyclomethicone and dimethiconol: 4.0% Reverse microlatex B: 3.5% B Water: q.s. 100% C Fragrance: 0.1% Sepicide ™ HB: 0.3% Sepicide ™ CI: 0.21% Parsol ™ MCX: 5.0% Titanium mica: 2.0% Lactic acid: q.s. pH = 6.5

EXAMPLE 32 Self-Tanning Emulsion

[0141] FORMULA A Lanol ™ 99: 15% Montanov ™ 68:  5.0% Parsol ™ MCX:  3.0% B Water: q.s. 100% Dihydroxyacetone:  5.0% Monosodium phosphate:  0.2% C Reverse microlatex A:  0.5% D Fragrance:  0.3% Sepicide ™ HB:  0.8% NaOH: q.s. pH = 5

[0142] The characteristics of the products used in the above examples are as follows:

[0143] Montanov™ 68 (cetearyl glucoside, cetearyl alcohol) is a self-emulsifying composition as described in WO 92/06778, sold by the company SEPPIC.

[0144] Montanov™ 202 (arachidyl glucoside, arachidyl alcohol+behenyl alcohol) is a self-emulsifying composition such as those described in WO 98/17610, sold by the company SEPPIC.

[0145] Micropearl™ M 305 is a silky water-dispersible powder based on crosslinked methyl methacrylate copolymer.

[0146] Micropearl™ M100 is an ultra-fine powder with a very soft feel sensation and a matt effect, sold by the company Matsumo.

[0147] Sepicide™ CI, imidazolinurea, is a preserving agent sold by the company SEPPIC.

[0148] Pemulen™ TR is an acrylic polymer sold by Goodrich.

[0149] Simulsol™ 165 is self-emulsifying glyceryl stearate, sold by the company SEPPIC.

[0150] Lanol™ 1688 is a non-greasy emollient ester sold by the company SEPPIC.

[0151] Lanol™ 14M and Lanol™ S are consistency factors sold by the company SEPPIC.

[0152] Sepicide™ HB, which is a mixture of phenoxyethanol, methylparaben, ethylparaben, propylparaben and butylparaben, is a preserving agent sold by the company SEPPIC.

[0153] Monteine™ CA is a moisturizer sold by the company SEPPIC.

[0154] Schercemol™ OP is a non-greasy emollient ester.

[0155] Lanol™ P is a stabilizing additive sold by the company SEPPIC.

[0156] Sepiperl™ N is a pearlescent agent, sold by the company SEPPIC, based on a mixture of alkylpolyglucosides such as those described in WO 95/13863.

[0157] Montanov™ S is a pearlescent agent, sold by the company SEPPIC, based on a mixture of alkylpolyglucosides such as those described in WO 95/13863.

[0158] Pecosil™ PS100 is dimethicone copolyol phosphate sold by the company Phoenix.

[0159] Lanol™ 99 is isononyl isononanoate, sold by the company SEPPIC.

[0160] Lanol™ 37T is glyceryl triheptanoate, sold by the company SEPPIC.

[0161] Sepifeel™ ONE is a mixture of palmitoylproline, magnesium palmitoyl glutamate and magnesium palmitoyl sarcosinate, such as those described in FR 2 787 323.

[0162] Solagum™ L is a carrageenan sold by the company SEPPIC.

[0163] Marcol™ 82 is a liquid paraffin sold by the company ESSO.

[0164] Lanol™ 84D is dioctyl malate, sold by the company SEPPIC.

[0165] Parsol™ MCX is ethylhexyl paramethoxycinnamate sold by the company Givaudan.

[0166] Eusolex™ 4360 is 3-benzophenone sold by the company Merck.

[0167] Dow Corning™ 245 Fluid is cyclomethicone, sold by the company Dow Corning.

[0168] Lipacide™ PVB is a palmitoyl wheat protein hydrolysate sold by the company SEPPIC.

[0169] Sepicontrol™ A5 is a mixture of capryloylglycine, sarcosine and extract of Cinnamon zylanicum, sold by the company SEPPIC, such as those described in international patent application PCT/FR 98/01313 filed on 23 Jun. 1998.

[0170] Capigel™ 98 is an acrylic copolymer sold by the company SEPPIC.

[0171] Lanol™ 2681 is a coconut caprylate/caprate mixture sold by the company SEPPIC. 

1. Composition comprising an oil phase, an aqueous phase, at least one surfactant of water-in-oil (W/O) type, at least one surfactant of oil-in-water (O/W) type and a branched or crosslinked polyelectrolyte, characterized in that: (a) the said composition is a self-reversible reverse microlatex comprising from 15% to 40% by weight and preferably from 20% to 30% by weight of the said polyelectrolyte, (b) the said polyelectrolyte is either a homopolymer based on a monomer containing a strong acid function, which is partially or totally salified, or a copolymer based on at least one monomer containing a strong acid function, which is copolymerized either with at least one monomer containing a weak acid function or with at least one neutral monomer, or a copolymer based on at least one monomer containing a weak acid function, which is copolymerized with at least one neutral monomer, or a copolymer based on at least one monomer containing a strong acid function, which is copolymerized with a monomer containing at least one weak acid function and with at least one neutral monomer, and (c) the mixture of the said surfactant of water-in-oil (W/O) type and of the said surfactant of oil-in-water (O/W) type has a total HLB number of greater than or equal to 8.5 and less than or equal to 11 and preferably greater than or equal to 9.5 and less than or equal to
 10. 2. Composition as defined in claim 1, in which the strong acid function of the monomer comprising it is the sulphonic acid function or the phosphonic acid function, which is partially or totally salified.
 3. Composition as defined in claim 2, in which the monomer comprising a strong acid function is 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid partially or totally salified in the form either of an alkali metal salt, or of the ammonium salt, or of the monoethanolamine salt or of an amino acid salt.
 4. Composition as defined in any one of claims 1 to 3, in which the weak acid function of the monomer comprising it is the carboxylic acid function.
 5. Composition as defined in claim 4, in which the monomer comprising a weak acid function is chosen from acrylic acid, methacrylic acid, itaconic acid, maleic acid or 3-methyl-3-[(1-oxo-2-propenyl)amino]butanoic acid, the said acids being partially or totally salified in the form either of an alkali metal salt, or of an ammonium salt, or a monoethanolamine salt or an amino acid salt.
 6. Composition as defined in any one of claims 1 to 5, in which the neutral monomer is chosen from acrylamide, 2-hydroxyethyl acrylate, 2,3-dihydroxypropyl acrylate, 2-hydroxyethyl methacrylate and 2,3-dihydroxypropyl methacrylate, or an ethoxylated derivative with a molecular weight of between 400 and 1 000, of each of these esters.
 7. Composition as defined in any one of claims 1 to 4, in which the polyelectrolyte is a crosslinked homopolymer of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid partially or totally salified in the form of the sodium salt or the ammonium salt.
 8. Composition as defined in either of claims 4 and 5, in which the polyelectrolyte is a crosslinked copolymer of acrylic acid partially or totally salified in the form of the sodium salt or the ammonium salt (a) and of acrylamide (b), in an (a)/(b) molar ratio of between 10/90 and 90/10.
 9. Composition as defined in any one of claims 1 to 3 and 6, in which the polyelectrolyte is a crosslinked copolymer of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid partially or totally salified in the form of the sodium salt, the ammonium salt, the monoethanolamine salt or the lysine salt (a) and of 2-hydroxyethyl acrylate (b), in an (a)/(b) molar ratio of between 30/70 and 90/10 and most particularly between 50/50 and 90/10.
 10. Composition as defined in any one of claims 1 to 5, in which the polyelectrolyte is a crosslinked copolymer of the sodium salt, the ammonium salt, the monoethanolamine salt or the lysine salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid (a) and of acrylic acid partially or totally salified in the form of the sodium salt, the ammonium salt, the monoethanolamine salt or the lysine salt (c), in an (a)/(c) molar ratio of between 30/70 and 90/10 and most particularly between 30/70 and 45/55.
 11. Composition as defined in any one of claims 1 to 3 and 6, in which the polyelectrolyte is a crosslinked copolymer of the sodium salt or the ammonium salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid (a) and of acrylamide (d) in an (a)/(d) molar ratio of between 50/50 and 30/70.
 12. Composition as defined in any one of claims 1 to 11, in which the polyelectrolyte is a crosslinked copolymer of the sodium salt, the ammonium salt, the monoethanolamine salt or the lysine salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid (a), of an acrylic acid partially or totally salified in the form of the sodium salt, the ammonium salt, the monoethanolamine salt or the lysine salt (c) and either of acrylamide (d) or 2-hydroxyethyl acrylate (e), in (a)/(c)+(d) or (a)/(c)+(e) molar proportions of between 10/90, 90/10 and (c)/(d) or (c)/(e) molar proportions of between 10/90 and 90/10.
 13. Composition as defined in any one of claims 1 to 12, characterized in that the polyelectrolyte is crosslinked and/or branched with a diethylenic or polyethylenic compound in a molar proportion, expressed relative to the monomers used, of from 0.005% to 1%, more particularly from 0.01% to 0.5% and most particularly from 0.1% to 0.25%.
 14. Composition as defined in claim 13, in which the crosslinking agent and/or the branching agent is chosen from diallyloxy acetic acid or a salt thereof, for instance sodium diallyloxyacetate, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diallylurea, trimethylolpropane triacrylate, methylenebis(acrylamide), triallylamine and diallyl tartramide, or a mixture of these compounds.
 15. Composition as defined in any one of claims 1 to 14, in which the oil phase represents from 25% to 50% and more particularly from 30% to 40% of its total weight.
 16. Process for preparing a composition as defined in any one of claims 1 to 15, characterized in that: a) an oil phase and surfactants are added, with stirring to an aqueous solution containing the monomers and the optional additives, so as to form a reverse microemulsion, and then b) the polymerization reaction is initiated and the said reaction is then left to proceed to form the reverse microlatex.
 17. Cosmetic, dermopharmaceutical or pharmaceutical composition, characterized in that it comprises at least one composition as defined in any one of claims 1 to
 15. 18. Use of a composition as defined in any one of claims 1 to 15, as a thickener and/or emulsifier in preparations intended for all kinds of industries, whether it is, for example, the textile industry, the paper industry or the paint manufacturing industry, and more particularly as a thickener for printing pastes based on pigments or dyes. 